Operating a processor in space, for example in a satellite, is crucial for mission accomplishment and for data integrity. Environmental constraints lead to try to improve the control of systems' tolerance to faults.
Currently, the radiation sensitivity technical problem is mitigated with solutions based on Triple Modular Redundancy (TMR) architectures or/and specific “rad-hard” (i.e. radiations hardened) digital integrated circuits. TMR architectures are well known fault tolerant techniques applicable to digital integrated circuits design up to system level architecture which consist in replicating three times a physical computing block performing the same task and to vote their outputs. A rad-hard digital integrated circuit is a (manufacturing level) approach which consists in using particular process technologies (e.g. Silicon-on-Insulator—SOD or/and circuit design patterns to improve the processor fault tolerance. Both approaches provide proven radiation fault tolerance effectiveness but they present several disadvantages.
These approaches are extremely expensive (for example in terms of acquisition costs and downstream engineering costs). They are based on old technologies offering very low processing power and do not take profit of commercial high performance technologies. They are also often mission dependant, i.e. not designed for scalability and therefore not reusable.
The published patent document EP2498184 discloses a device which has a software layer i.e. hypervisor (202), centralizing exchanges between a processor and an application (201) and implementing management mechanisms of fault tolerances. A programmable electronic component forms an interface between the processor and a memory unit e.g. synchronous dynamic RAM and a data input and output interface. One of the mechanisms is a reset function at known state of the processor, where the function is periodical with a configurable period. The mechanism is reset to the known state by a resetting signal issued by the programmable electronic component. This approach presents limitations.
Thus, there is the need of solutions to solve the aforementioned problems. Embodiments of the present invention offer such solutions, at least in part.